Method of making a coupling device



Dec. 14, 1965 ANTALEK 3,222,760

METHOD OF MAKING A COUPLING DEVICE Original Filed June 22, 1959 2,Sheets-Sheet 1 'E-TL FIG.2

I 1 l n I l l I n I I INVENTOR.

JOHN J. ANTALEK BY 74 M,KMMW;%

ATTORNEYS Dww 14, 1965 J. J. ANTALEK METHOD OF MAKING A COUPLING DEVICEOriginal Filed June 22, 1959 2 Sheets-Sheet 2 FI6.5 FIG.7

A INVENTORU JOHN J. ANTALE'K Y 22 My ATTORNEYS 3,222,760 METHGD UlFMAKING A CQUPLING DEVICE John .I. Antalelt, Glenview, Ill., assignor toTRW Inc., a corporation of ()hio Original application June 22, 1959,Ser. No. 821,802, now Patent No. 3,130,350, dated Apr. 21, 1964. Dividedand this application Dec. 6, 1963, Ser. No. 328,547 13 (Jlairns. (Cl.29-1555) The present invention relates to coupling devices such astransformers, and, more particularly, to tuned coupling devices andtransformers of the type used in radio and television circuits. Forexample, the invention may be employed in a transformer arrangementwherein the windings of the transformer are wound on a tubular coil formand one or more tuning capacitors are connected to the windings of thetransformer, the entire assembly being positioned within a so-calledshield can which is mounted to the chassis of the receiver or otherelectronic circuit. This application is a division of my copendingapplication Serial No. 821,802, now Patent No. 3,130,350, filed June 22,1959, and assigned to the same assignee as the present invention.

While many coupling device arrangements have been proposed in the pastwherein the tuning capacitors are mounted within the shield can and areconnected to the indings of the transformer, these arrangements have ingeneral not been readily adaptable to mass production techniques. On theother hand, those constructions which have been designed with massproduction methods in mind have not provided a suitably reliableelectrical connection between the tuning capacitors and the transformerwindings, such arrangements relying on pressure between the terminals ofthe transformer and the plates of the capacitors for establishing therequisite electrical connec tion. In one such prior art arrangementemploying pres sure to maintain electrical contact, the capacitors arein the form of plated mica strips which are positioned in a sandwichtype of construction in the base of the transformer, connection to theterminals of the transformer being solely by the pressure exerted on thesandwich by means of a spring washer and stud arrangement extendingthrough the center of the transformer base.

It is, therefore, an object of the present invention to provide a newand improved coupling device arrangement wherein good electrical contactis established and maintained between the electrodes of a disc typecoupling unit and the terminals of the device, while, at the same time,providing a construction which may be readily manufactured on a massproduction basis.

It is another object of the invention to provide a new and improvedtransformer assembly wherein one or more tuning capacitors can beconductively bonded to the terminals of the transformer by means of asingle dip-soldering operation, or the like.

It is still another object of the present invention to provide a new andimproved base construction which facilitates fabrication of transformerassemblies on a mass production basis.

A further object of the present invention is to provide a new andimproved base member construction for a transformer assembly wherebyeither large or small diameter coil forms may be employed with the samebase member to facilitate assembly of the transformers on a massproduction basis.

It is a still further object of the present invention to provide a newand improved method of assembling transformer components wherein thetuning capacitors are first positioned on the base member and secured tothe terminals of the transformer by means of a dip-soldering nitedStates Patent f ice operation before the coil form which supports thetransformer windings is secured to the base member.

It is a still further object of the present invention to provide a newand improved shield can arrangement for a transformer assembly whichfacilitates insertion of the transformer assembly within the can andwhich is readily secured to the base member of the transformer.

Another object of the present invention resides in the provision of anew and improved coupling device arrangement which is reliable inoperation, simple in design and may be readily produced on a massproduction basis.

Briefly, in accordance with one phase of the present invention, the basemember of the coupling device is provided with a top opening recesswithin which the tuning capacitor, or other disc type unit havingexposed electrodes on opposite sides thereof, is positioned on edge andis held in position by means of inturned arm portions of the terminalmembers of the device which are secured to the base member. These armportions engage the edge positioned disc type unit at points spacedabove the top surface of the base member so that the base member with adisc unit held therein may be inverted and conductively bonded to theinturned terminal arm portions by means of a single dip-solderingoperation.

If the coupling device is a transformer the coil form is secured to thebase member after this dip-soldering operation and the ends of thewindings on the coil form are then secured to the transformer terminals.In accordance with a further feature of the present invention, the basemember may be provided with a tubular coil form mounting sleeve which isadapted to receive either a large diameter or a small diameter coil formso that a universal mounting arrangement for different size coil formsis provided. in accordance with a still further phase of the presentinvention, the shield can of the coupling device is provided withstraight sides and a central opening in the top thereof defined by meansof a vertically extending sleeve portion, the portion of the shield canconnecting the straight sides and this sleeve portion being inclined soas to act as a guide for the upper end of the coil form and facilitateinsertion of the upper end of the coil form into the central openingupon assembly of the coupling device in the can. In accordance withstill another phase of the present invention, a snap locking arrangementis provided for securing the shield can on the base member withoutrequiring any lugs to be turned down to hold the coupling device withinthe can.

The invention, both as to its organization and operation, together withfurther objects and advantages thereof, will best be understood byreference to the following detailed description taken in connection withthe accompanying drawings, in which:

FIG. 1 is a front elevation view of a coupling device embodying thefeatures of the present invention, portions of the shield can of thisassembly being broken away to show certain features of construction;

FIG. 2 is a right side elevation view of the coupling device with theshield can broken away and a portion of the coil form assembly beingshown in section through the center line thereof.

FIG. 3 is a sectional view taken along the lines 3-3 of FIG. 2;

FIG. 7 is a sectional view taken along the lines 77 of FIG. 6;

FIG. 8 is a perspective view of the base member of FIG. 1 showing themanner in which a capacitor or other disc type unit is supported thereinprior to the dip soldering operation;

FIG. 9 is a sectional view taken along the lines 99 of FIG. 8;

FIG. 10 is a sectional view taken along the lines 1010 of FIG. 9; and

FIG. 11 is a sectional view taken along the lines 1111 of FIG. 4.

Referring now to the drawings, there is shown a coupling devicearrangement according to the present invention which is indicatedgenerally at 11 and comprises a base member indicated generally at 12, acoil form 13 which is positioned on the base member 12 and carries apair of multilayer coils 14 and 15 thereon, and a shield can indicatedgenerally at 16. The coils 14 and 15 may conveniently be wound ofinsulated copper wire on the coil form 13 and the ends of these coilsare secured to terminal members indicated generally at 20, 21, 22 and23, these terminal members being secured in the base member 12 by meansto be discussed in more detail hereinafter. It will be understood thatalthough the transformer shown in FIG. 1 utilizes a pair of coils 14 and15, a greater or lesser number of coils may be provided on the form 13if desired.

In order to adjust the magnetic coupling between the coils 14 and 15 aswell as to change the inductance of each of these coils, theferromagnetic core members 25 and 26 (FIG. 2) may be adjustablypositioned in the coil form 13. The coil form 13 may be provided with aplurality of thin ribs 27 which extend longitudinally along the innersurface of the coil form 13 whereby the cores 25 and 26 may beadjustably positioned with respect to the coils 14 and 15, thisconstruction of the coil form 13 being described and claimed in US.Letters Patent No. 2,838,738, granted to John I. Antalek and Robert W.Saville on June 10, 1958. While such construction of the coil form 13cooperates with the specific form of base construction of the presentinvention, it will be understood that any other suitable coil form andtuning slug arrangement may be employed whereby a variable inductancedevice is provided insofar as the other features of the presentinvention are concerned. Furthermore, it will be understood that thecoils 14 and 15 need not be variable insofar as the present invention isconcerned although it is customary to provide variation of thetransformer windings to facilitate alignment of the transformer once itis assembled in its electronic circuit.

Considering now the manner in which the tuning capacitors or other disctype units in the assembly of the present invention are supported on thebase member 12 and are conductively bonded to the transformer terminals,attention is first directed to the terminals 20 to 23, inclusive,themselves and more particularly to FIGS. 9 and 10 which show thedetails of the terminal 21. As there shown, the terminal 21 is providedwith a bifurcated upper portion comprising a normally verticallypositioned arm portion 30 and an inturned arm portion 31, thesebifurcations or arm portions 30 and 31 being positioned above the upperrim 32 of the base member 12.

The terminal 21 is mounted in a vertically extending slot 35 provided inthe base member 12, similar slots 36, 37 and 38 being providedrespectively for the terminals 20, 22 and 23. Each of these slots, suchas the slot 35, is provided with a groove 40 which is adapted to receivean outwardly protruding reinforcing rib 41 provided in the lower portionof the terminal member 21 and there is also provided a groove 42 in theother side of the slot 35, the groove 42 having a sloping shoulder orstep 42a at the upper end thereof over which a tang or projection 44which is struck out of the body portion of the terminal 21 is adapted tosnap and thereby retain the terminal 21 in position after it has beeninserted into the slot 35 from the top of the base 12, as best shown inFIG. 10. The slot 35 is also provided with shoulders 35a at the endsthereof and the terminal 21 is provided with a relatively wide portionabove the tang 44 so that this wide portion is held against theshoulders 35a when the tang 4-4 is snapped in place, as best shown inFIG. 9. With this construction the terminal 21 is rigidly held and isprevented from twisting within the slot 35 so that the inturned armportion 31 thereof can exert a substantial size thrust on the edgemounted disc unit as will now be described.

In accordance with an important feature of the present invention, theinturned arm portions of opposed pairs of terminal members are employedto support a tuning capacitor or other disc type unit on edge on thebase member 12 by engagement with opposite sides of the tuningcapacitor. More particularly, considering the pair of terminals 20 and21, the inturned arm portion 50 of the terminal 20 and the inturned armportion 31 of the terminal 21 are adapted to engage the opposite sidesof a disc type tuning capacitor indicated generally at 51, the capacitor51 being supported on edge on the base member 12.

The disc type unit 51 comprises a wafer-like self supporting baseportion 52 (FIG. 11) constructed of a solid dielectric material, such,for example, as a ceramic material, the plates of the capacitor unit 51consisting of two metallic layers 53 and 54 which are provided on theopposite flat surfaces of the dielectric member 52, the edge of thedielectric member 52 being, however, free from conductive material. Itwill thus be understood that the plates or electrodes 53, 54 areseparated by the dielectric material 52 and having a capacitancetherebetween which is dependent upon the areas of the plates and thethickness and dielectric constant of the base member 52. If it isdesired, the capacitor 51 may be constructed by means of the arrangementdisclosed in the copending application of Hal F. Fr uth, S. N. 514,880,filed June 13, 1955, now abandoned, wherein there is disclosed anarrangement in which the dielectric core member is coated over theentire surface thereof with a conductive layer and thereafter theconductive material is removed from the edge of the disc to provide acapacitor consisting of conductive surface portions separated by thedielectric core member. It will also be understood that the capacitor 51may alternatively be formed by painting or printing a conductive varnishor metal on the opposed fiat surfaces of the dielectric disc 52 so as toprovide the capacitor plates 53 and 54, insofar as the features of thepresent invention are concerned. However, it is pointed out that inaccordance with an important feature of the present invention, theopposed electrodes 53 and 54 of the disc type unit, such as thecapacitor 51, are not coated with any insulation or impregnationmaterial but instead are left bare so as to permit the inturned armportions 50 and 31 to establish electrical contact thereto.

Considering now the manner in which the capacitor 51 is supported on thebase member 12, the base member 12 is provided with a top openingrecess, the edge of the capacitor 51 resting on the bottom surface 55 ofthis top opening recess. In order to facilitate positioning of thecapacitor 51 on edge on the base member 12 with the arm portions 50 and31 in engagement with opposite sides thereof, the base member 12 isprovided with a pair of opposed positioning posts or studs and 61adjacent the terminals 20 and 21 which extend upwardly from the bottomsurface 55 of the recess in the base member 12, the studs 60 and 61being connected to the side wall of the base member 12 by means of theweb portions 62 and 63 (FIG. 8). In addition, a further positioning postor stud 64 extends upwardly from the bottom surface 55 of the topopening recess in the member 12, the stud 64 being spaced from thepositioning stud 61, and an inwardly projecting vertically extending ribor lug portion 65 (FIG. 3) is provided on the outer wall 66 of the basemember 12 adjacent to but spaced from the positioning stud 611.

It will thus be seen that the positioning posts 60, 61 and 64 and theprojecting lug 65 define an elongated narrow slot which is adapted toreceive the tuning capacitor 51 on edge and loosely supports the same onthe base member 12;. However, it will also be noted that as soon as thearm portions 55) and 31 are moved into engagement with the oppositesides of the capacitor 51 these arm portions exert a twisting action onthe disc capacitor 51, due to the fact that the arm portions 59 and 31engage the capacitor at laterally spaced points thereon, so that thecapacitor 51 is urged against the side of the positioning post 64 and isalso urged against the side of the projecting lug 65, as bestillustrated in FIG. 3. Furthermore, it will be noted that since it isnecessary to move the arm portions 5tl and 31 sidewise away from theirinitial positions when the tuning capacitor is positioned therebetweenthese arm portions continuously exert a sidewise thrust on the opposedsides of the capacitor 51 and function to hold this capacitor in anupright position on the base member 12. In this connection it will benoted that the arm portions 50 and 31 are provided respectively with theoppositely directed right angle end portions 71D and 71 which actuallycontact the opposed bare electrodes on opposite sides of the capacitor51 so that contact to the plates of the capacitor 51 is establishedthrough the end portions 719 and 71 at a localized area on the plates.

While the post 64 and lug 65 are of substantial height so that when thecapacitor 51 is urged into engagement with the sides thereof thecapacitor is held upright on the base 12, it will be noted that thecontact making end portions '71 and 71 of the arm portions 59 and 31,respectively, contact the bare plates of the capacitor 51 at pointsspaced considerably above the upper surfaces of the base member 12including the tops of the posts 60, 61, 64 and the lug 65. Thisconstnuction is provided so that in accordance with a further importantfeature of the present invention a good conductive bond may beestablished between the end portions 70 and 71 and the electrodes of thecapacitor 51 and reliance is not placed solely on a pressure contactbetween these members to maintain good electrical connection. Moreparticularly, after the capacitor 51 has been inserted into the basemember 12 and the arm portions 5th and 31 moved into engagementtherewith, it is held in this position due to the above describedtwisting action which holds the capacitor against the post 64 and thelug 65. This pressure is sufiicient that the base member may be invertedwithout the capacitor 51 dropping out of its slot in the base member 12.Accordingly, after the capacitor 51 has been positioned in the basemember as shown, for example, in FIG. 8, the base member is inverted andis dipped into a pot of solder to a depth sufficient to submerge the endportions 711 and 71 but not to a depth sufiicient to cause any portionsof the base member 12 itself to come in contact with the melted solder.The base member 12 is then removed from the molten solder with theresult that the end portions 70 and 71 are conductively bonded to theopposed electrodes of the capacitor 51. More partioularly, the entireupper surface of each of the plates 53 and 5'4 is covered with a film ofsolder 53a and 54a (FIG. ll) and a fillet of solder is provided aroundeach of the end portions 70 and 71 so that a strong physical as well asan electrically conductive bond is established between the end portions74 and 71 and the conductive plates 53 and 54 of the capacitor 51. Onesuch fillet of solder is indicated at 74 in FIG. 4 whereby the endportion 71} of the arm portion 50 is conductively bonded to the plate 53of the capacitor 51. However, it will be noted that while thedip-soldering operation completely covers the upper portions of theplates 53 and 54 of the capacitor 51, the solder does not adhere to theedge of the dielectric disc 52 so that the plates of the capacitor 51are not conductively shorted together. Furthermore,

d the solder films 53a and 54a do not appreciably change the capacitanceof the capacitor 51 since they do not affect either the area of theplates 53 and 54 or the spacing thereof.

The base member 12 is also arranged to support a second tuningcapacitor, indicated generally at '76, between the spaced apartterminals 22 and 23. More particularly, the positioning posts 78 and 79are provided adjacent the terminals 22 and 23, respectively, these postsbeing similar to the positioning posts 60 and 61 described above, apositioning post 80 is positioned in spaced relation to the post 78 anda vertically extending lug 81 on the base 12 is provided in spacedrelation to the post 79. The inturned arm portions 85 and 86 of theterminals 22 and 23, respectively, are provided with oppositely directedend portions 88 and 89 which are adapted to engage the opposite sides ofthe capacitor 76 at laterally spaced points thereon so that a twistingaction is exerted on this capacitor and it is urged against the sides ofthe positioning post 80 and the lug 81 so that it is held on edge in thebase 12, as shown in FIG. 3.

In the actual manufacture of the transformer in accordance with thepresent invention both the capacitors 51 and 76 are assembled on thebase 12 and positioned between the restraining arm portions of theadjacent terminal members before the dip-soldering operation isperformed. Accordingly, all four solder connections may be performed inone dip soldering operation so that a conductive bond is established toboth of the tuning capacitors of the transformer in a single solderingoperation. Furthermore, it will be appreciated that a number of suchbase assemblies with tuning capacitors mounted thereon may be mounted ina common jig and inverted so that they are all soldered in a singleoperation thus effecting a material saving in manufacturing time andlabor over previous arrangements. Attention is also directed to the factthat the dip soldering operation whereby the terminal members of thetransformer are conductively bonded to the electrodes of the tuningcapacitors is performed before the coil form 13 is assembled on the basemember 12, and before the leads from the coils positioned on the coilform are connected to the vertically extending portions of the terminalmembers. In this connection it will be understood that the verticallyextending portions of the terminal members 20 to 23, inclusive, such asthe vertical bifurcation 36 of the terminal 21, are also immersed in themolten solder during the above described dip-soldering operation.However, this operation only has the effect of tinning the ends of thevertically extending terminal portions, such as the portion 30, and thusfacilitates the connection of the coil leads to these terminals at alater time. However, if desired, the vertically extending terminalportions, such as the portions 30, may be bent outwardly so that they donot contact the solder during the dip-soldering operation if, for anyreason, it is not desired to tin these terminal portions.

Considering now the manner in which the coil form 13 is assembled on thebase member 12, a transverse reinforcing rib is provided across thebottom of the recess in the base member 12 in the center of which ribthere is provided an annular mounting sleeve 96 which extends upwardlyfrom a circular base portion 27. The mounting sleeve 96 is arranged tosupport either the relatively small diameter coil form 13 or arelatively large diameter coil form 98 (FIGS. 6 and 7). Moreparticularly, in order to receive the relatively small diameter coilform 13 within the mounting sleeve 9-5, this sleeve is provided with astepped portion 1% of somewhat smaller internal diameter which extendsonly partially up to the length of the sleeve 96, the stepped portion 1%being provided with a series of vertically extending inwardly projectingribs 101 which function to grip the outer surface of the coil form 13when it is inserted into the step portion of the mounting sleeve 96. Aninwardly extending shoulder 102 is provided at the bottom of themounting sleeve 96 so as to seat the bottom of the coil form 13. It willbe noted that the coil form 13 is secured within the mounting sleeve 96by engagement with only the stepped portion 100 thereof so that theoutward force exerted on the mounting sleeve 96 when the coil form 13 isinserted therein is applied only to the base portion of the sleeve andhence cracking or splitting of the sleeve is avoided.

The mounting sleeve 96 is also provided with a series of closely spacedvertically extending ribs 105 on the outer surface thereof. The ribs 105are provided for the purpose of interlocking with the internallongitudinally extending ribs 106 of a relatively large diameter coilform 98 when this coil form is inserted over the Outside of the mountingsleeve 96, the coil form 98 being forced over the sleeve 96 until itseats on the circular base portion 97. Due to the interlocking of theribs 105 and 106 the coil form 98 is not only firmly seated on themounting sleeve 96 but is also prevented from rotating with respect tothe base member 12. In this connection it will be understood that theribs 106 may serve the additional function of adjustably positioning thetuning slugs within the coil form 93, as described in the aboveidentified Patent No. 2,838,738; Also it will be noted that thepositioning posts 6-1- and 80 are spaced from the outside ribs 105 onthe mounting sleeve 96 by an amount sufficient to permit the insertionof the large diameter coil form 98 over the sleeve 96. It will also benoted that the positioning posts 64 and 80 serve the additional purposeof providing a positioning means for the tuning capacitors whilepermitting the coil form 98 to be inserted over the mounting sleeve 96after the tuning capacitors have been soldered in place in the mannerdescribed above.

The coils 14 and 15 may be wound on the coil form 13 either before orafter this coil form is positioned on the base member 12. However, itwill be understood that if the coils 14 and 15 are wound on the coilform 13 after this coil form is secured to the base member 12, theupstanding terminal portions, such as the portion of the terminalmembers of the transformer are preferably bent outwardly so as toprovide clearance for the coil winding mechanism in the event that thecoil is wound relatively close to the base member 12. It has been foundthat the procedure of winding the coils 14 and 15 after the coil form 13has been secured to the base member 12 results in a somewhat simplermanufacturing technique in that the ends of the respective coils canfirst be secured to the corresponding upstanding terminal portions sothat the coil winding operator can trace the start and finish coil leadsmore easily. In this connection it will be understood that the start andfinish leads 130 and 131 of the coil 14 are connected to a pair ofterminal members which are positioned on opposite sides of the recess inthe base member so that the tuning capacitor connected between theinturned arm portions of these terminal members is connected across thecoil. Thus, the lead 130 and 131 are connected to the verticallyextending portions 132 and 133 of the terminals 23 and 22, respectively,so that the tuning capacitor 76 is connected across the coil 14. In asimilar manner the leads 135 and 136 may be connected to the upstandingterminal portions of the terminals 21 and 20, respectively, so as toconnect the capacitor 21 across the winding 15. It will be noted thatthe upstanding terminal portions, such as the portion 30 of the terminal21, are provided with a notch 136 in the upper end thereof to facilitateconnection of the coil leads to these terminals, it being necessary onlyto hook the coil leads over the notches 138 and wrap the lead one or twoturns around the terminal. After the coil leads have been secured to theupstanding terminal portions in the manner described above, they may beconveniently dip-soldered to these terminals by bending the terminalsoutwardly so that they extend beyond the edge of the base member 12.When so bent the terminals with coil leads attached thereto may belowered into a pot of molten solder so that the coil leads on one sideof the base member may both be soldered simultaneously to theirrespective terminals, it being understood that the transformer assemblyis not lowered into the solder sutliciently to permit the solder tocontact either the base member 12 or the coils on the coil form 13. Thetransformer assembly may then be turned over and the terminals of theopposite side of the base member soldered by a similar dip-solderingoperation, after which all four of the terminal members are bent back totheir initial vertical position. The transformer assembly is then readyfor the shield can 16 to be assembled thereon.

In this connection it will be noted that the base member 12 is providedwith a pair of terminal receiving slots 107 and 108 within which may bepositioned terminals similar to the terminals 20 to 23, inclusive, butwhich are, however, not provided with an inturned arm portion such asthe arm portion 31 of the terminal 21. These intermediate terminals maybe employed to establish connection to other desired connection pointson the coils positioned on the coil form 13, such, for example, as acenter tap for either of the coils 14 or 15. However, since no tuningcapacitor is to be connected across these intermediate terminals theinturned arm portions thereof are not required.

Considering now the manner in which the shield can 16 is formed inaccordance with the present invention, it is first pointed out that thisshield can may be provided with a grounding lug or terminal 110 whichmay be secured to the bottom portion of the can 16 by any suitable meanssuch as rivets or the like, the ground strap 110 extending downwardlyalong the side of the base member 12 so that it projects below thebottom of the shield can 16. In the center of the top portion of theshield can 16 there is provided a vertically extending tubular portionwhich defines an opening adapted to receive the upper end of the coilform 13. In accordance with a further feature of the invention, theentire top portion 116 of the shield can intermediate the straight sidesthereof and the central sleeve 115 is formed so that it slopes inwardlyat a substantial angle to the horizontal to form a conically shaped top.Accordingly, as the shield can 16 is inserted over the transformerassembly and the upper end of the coil form engages the conical section116, this section acts as a guide for the upper end of the coil form andfacilitates insertion thereof into the sleeve portion 115 as the shieldcan is moved downwardly to enclose the base member 12. Since the entiretop portion of the shield can 116 is conically shaped no transversesurfaces are presented to the end of the coil form 13 with the resultthat this coil form slides easily into the sleeve 115, at which pointthe coil form 113 is accurately centered with respect to the shield can16 and the base 12. As the shield can 16 is forced downwardly over thebase member 12 a snap locking arrangement is provided so that the shieldcan is secured to the base member 12 without requiring the bending ofany lug portions or other arrangements for holding the shield can inplace. More particularly, there is provided on two opposed sides of thebase member 12 a pair of wedge-shaped projections 120 and 121 whichcooperate with a pair of elongated transverse slots 122 and 123 in theshield can 16 to hold the shield can in place. As the shield can isinserted over the base member 12 the wedge portions 120 and 121 forcethe sides of the shield can outwardly until the shoulders thereof havebeen snapped into place in the slots 122 and 123 at which point theshield can becomes secured to the base member 12 and cannot readily beremoved due to the fact that the shoulders of the wedges 120 and 121engage the bottom edges of the slots 122 and 132 and prevent suchremoval.

While particular embodiments of the invention have been shown, it willbe understood, of course, that the invention is not limited thereto,since many modifications may be made, and it is therefore contemplatedby the appended claims to cover any such modifications as fall withinthe true spirit and scope of the invention.

What is claimed as new and is desired to be secured by Letters Patent ofthe United States is:

1. The method of making a transformer of the type which includes a basemember having a plurality of terminal members thereon, a coil form forsupporting a coil and a capacitor having opposed electrodes, whichcomprises a steps of positioning said capacitor on said base member withsaid terminal members in engagement with the electrodes of saidcapacitor at points spaced above the upper surface of said base member,conductively bonding said terminal members to said electrodes byimmersing the upper portion of said capacitor and the ends of saidterminal members engaging said opposed electrodes in molten solder, thenmounting said coil form on said base member, and connecting the ends ofa coil wound on said coil form to said terminal members.

2. The method of making a transformer as recited in claim 1, whereinsaid coil is wound on said coil form after said coil form is mounted onsaid base member by first attaching one end of a length of wire to oneof said terminal members, winding said length of wire on said coil formto provide a coil thereon and then attaching the other end of saidlength of wire to another of said terminal members.

3. The method of making a transformer as recited in claim 1 whichincludes the step of conductively bonding said connected ends of saidcoil to said terminal members by dip soldering.

4. The method of making a transformer of the type which includes a basemember having a plurality of terminal members thereon, a coil form forsupporting a coil and a disc capacitor having opposed electrodes, whichcomprises the steps of positioning said capacitor on said base memberwith said terminal members in engagement with the electrodes of saidcapacitor at points spaced above the upper portion of said base member,moving said base member to an inverted position while maintaining saidcapacitor positioned on said base member by engagement of said terminalmembers with said electrodes, conductively bonding said terminal membersto said electrodes by dip-soldering while said base member is in saidinverted position, then mounting said coil form on said base member, andconnecting the ends of a coil Wound on said coil form to said terminalmembers.

5. The method of making a transformer of the type which includes a basemember having a plurality of terminal members thereon, a coil form forsupporting a coil and a capacitor of the disc type having opposedelectrodes separated by a layer of dielectric, which comprises the stepsof positioning said capacitor on edge on said base member with a firstportion of said terminal members in engagement with said opposedelectrodes of said capacitor, conductively bonding said first portionsof said terminal members to said electrodes by immersing the same inmolten solder, then mounting said coil form on said base member, andconnecting the ends of a coil wound on said coil form to a secondportion of said terminal members.

6. The method of making an inductance-capacitance assembly of the typewhich includes a base member having a plurality of terminal membersthereon, a coil form for supporting a coil and a disc capacitor havingopposed electrodes, which comprises the steps of positioning saidcapacitor on said base member with a first portion of said terminalmembers in engagement with said opposed electrodes of said capacitor atpoints spaced above the upper surface of said base member, conductivelybonding said first portions of said terminal members to said electrodesby dip-soldering and without bringing said base member into contact withthe molten solder, then mounting said coil form on said base member, andconnecting the ends of a coil wound on said coil form to a secondportion of said terminal members.

7. The method of making an inductance-capacitance assembly as recited inclaim 6 which includes the steps of bending said second portions of saidterminal members with said ends connected thereto beyond the edge ofsaid base member, and conductively bonding said connected ends to saidsecond portions of said terminal members by immersing the same in moltensolder without immersing said base member.

8. The method of making an inductance-capacitance assembly as recited inclaim 6 which includes the steps of bending said second portions of saidterminal members with said ends connected thereto beyond the edge ofsaid base member, conductively bonding said connected ends to saidsecond portions of said terminal members by immersing the same in moltensolder Without immersing said base member, and then bending said secondportions of said terminal members to points within the periphery of saidbase member to permit enclosure of said base member and coil form withina metallic housing.

9. The method of making an inductance-capacitance assembly as recited inclaim 6, wherein said coil is wound on said coil form after said coilform is mounted on said base member by first attaching one end of alength of wire to said second portion of one of said terminal members,winding said length of wire on said coil form to provide a coil thereon,and then attaching the other end of said length of wire to said secondportion of another of said terminal members.

10. The method of making an inductance-capacitance assembly whichcomprises the steps of positioning a disc capacitor between spring armportions of a pair of terminals mounted on a base member with saidspring arm portions in engagement with conductive electrode portions onopposite sides of said disc capacitor, moving said base member with saidcapacitor positioned thereon to a position in which the points ofengagement of said spring arm portions with said conductive electrodeportions are below said base member and conductively bonding said springarm portions to said conductive electrode portions by immersing the samein molten solder, then mounting a coil form on said base member, andconnecting the ends of a coil wound on said coil form to other portionsof said terminal members.

11. The method of making an inductance-capacitance assembly as set forthin claim 10 wherein said second portions of said terminal members areconductively bonded to said connected ends of said coil by immersing thesame in molten solder without bringing said base member and coil forminto contact with the molten solder.

12. The method of making an inductance-capacitance assembly whichcomprises the steps of positioning a disc capacitor between spring armportions of a pair of terminals mounted on a base member with saidspring arm portions in engagement with conductive electrode por tions onopposite sides of said disc capacitor, said spring arm portions engagingsaid electrode portions at points above the upper edge of said basemember, moving said base member with said capacitor positioned thereonto a position in which the points of engagement of said spring armportions with said conductive electrode portions are below said basemember and conductively bonding said spring arm portions to saidconductive electrode portions by immersing the same in molten solder,said spring arm portions engaging said opposite sides of said capacitorwith sufficient force to hold said capacitor on said base member duringsaid soldering operation, then mounting a coil form on said base member,and connecting the ends of a coil wound on said coil form to otherportions of said terminal members.

13. The method of making an inductance-capacitance assembly whichcomprises the steps of positioning a disc capacitor on edge within thetop opening recess of a base member and between spring arm portions of apair of terminals extending through said base member, said spring armportions extending above the upper edge of said base member and engagingconductive electrode portions on opposite sides of said disc capacitor,moving said base mem- 1 1 ber with said capacitor positioned thereon toa position in which the points of engagement of said spring arm portionswith said conductive electrode portions are below said upper edge ofsaid base member and conductively bonding said spring arm portions tosaid conductive electrode portions by immersing the same in moltensolder, said spring arm portions engaging said opposite sides of saidcapacitor with sufficient force to hold said capacitor within saidrecess in said base member during said soldering operation, thenmounting a coil form on said base member, and connecting the ends of acoil wound on said coil form to second portions of said terminal memberswhich extend above said upper edge of said base member.

References Cited by the Examiner UNITED STATES PATENTS 2,751,665 6/1956De Roovere 29-1555 2,869,041 1/1959 De Cola 29155.5 2,946,026 7/1960Rollefson 29-155.5 2,974,258 3/1961 Garthwaite 29155.5

WHITMORE A. WILTZ, Primary Examiner.

1. THE METHOD OF MAKING A TRANSFORMER OF THE TYPE WHICH INCLUDES A BASEMEMBER HAVING A PLURALITY OF TERMINAL MEMBERS THEREON, A COIL FORM FORSUPPORTING A COIL AND A CAPACITOR HAVING OPPOSED ELECTRODES, WHICHCOMPRISES A STEPS OF POSITIONING SAID CAPACITOR ON SAID BASE MEMBER WITHSAID TERMINAL MEMBERS IN ENGAGEMENT WITH THE ELECTRODES OF SAIDCAPACITOR AT POINTS SPACED ABOVE THE UPPER SURFACE OF SAID BASED MEMBER,CONDUCTIVELY BONDING SAID TERMINAL MEMBERS TO SAID ELECTRODES BYIMMERSING THE UPPER PORTION OF SAID CAPACITOR AND THE ENDS OF SAIDTERMINAL MEMBERS ENGAGING SAID OPPOSED ELECTRODES IN MOLTEN SOLDER, THENMOUNTING SAID COIL FORM ON SAID BASE MEMBER, AND CONNECTING THE ENDS OFA COIL WOUND ON SAID COIL FORM TO SAID TERMINAL MEMBERS.